Norovirus suspected in nearly 25% of Sammamish school's students

Nearly a quarter of Elizabeth Blackwell Elementary School students in Sammamish were home sick on Tuesday, and county health officials suspect it could be a norovirus outbreak.

More than 120 of the school's 560 students were out sick, and 15 more were sent home during the day, said Kathryn Reith, spokeswoman for Lake Washington School District. Nine staff members were out sick Monday and eight had stayed home sick Tuesday. The district heard that some parents kept their children home as a precaution, Reith said.

No other schools in King County reported high numbers of ill students this week, but it's not uncommon to see waves of these kinds of illness move through schools and other institutions, said James Apa, spokesman for Public Health -- Seattle & King County.

The agency has not confirmed the cause through lab work, but based on reports from the school's nurse, the agency believes that norovirus is the likely culprit, Apa said.

Norovirus is a common virus that causes nausea, vomiting, diarrhea, chills, fever and headache.

Most people recover within a day or two, although people who are infected are contagious from the moment they begin feeling ill until at least three days after symptoms end, according to Public Health information.

Nearby Margaret Mead Elementary, with more than 600 students, reported just over 10 percent of its students out sick on Monday. By Tuesday, all but about 20 students were back to school, Reith said.

Districts are required to notify the county's public-health agency if more than 10 percent of the student enrollment is out sick.

So far this year, Public Health has had 45 reports of norovirus outbreaks in institutions such as schools, nursing homes and hospitals throughout the county, Apa said.

Public Health also sees at least a handful of schools every year in which 20 percent or more of students stay home sick, Apa said.

In February, Bishop Blanchet High School in North Seattle voluntarily closed down after more than 300 of the Catholic school's 1,080 students called in sick, mostly with flu symptoms.

Blackwell Elementary, which teaches kindergarten through sixth grade, plans to be open today.

The school is reinforcing hygienic steps, such as asking students to frequently wash their hands, wipe down their desks and clean any frequently touched surfaces, said Nancy Johnson, health services supervisor for Lake Washington School District.

Adult helpers are also serving students at the school's salad bar during lunch. Normally, students help themselves, she said.

"It's very contagious," Johnson said. "There's an emphasis in hand-washing and sanitizing the environment. And stay home if you're ill."

Rachel Tuinstra: 206-515-5637 or rtuinstra@seattletimes.com